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www.hydrol-earth-syst-sci-discuss.net/5/2491/2008/
doi:10.5194/hessd-5-2491-2008
© Author(s) 2008. This work is distributed
under the Creative Commons Attribution 3.0 License.
Geostatistical modeling of spatial variability of water retention curves
1Department of Ecoregion Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
2Faculty of Business Administration, Toyo University, Tokyo 112-8606, Japan
3Department of Environmental Sciences, University of California, Riverside, CA 92521, USA
Abstract. This study compares the performance of two geostatistical approaches, parametric and non-parametric, to evaluate the spatial distribution of water retention curves. Data used in this study were obtained from the Las Cruces trench site database that contains water retention data for 448 soil samples. In a commonly used parametric approach, three standard water retention models, i.e. Brooks and Corey (BC), van Genuchten (VG), and log-normal (LN), were first fitted to each data set. For each model, a cross validation procedure was used to estimate parameters at each sampling location, allowing computation of prediction errors. In a rarely used non-parametric approach, a cross validation procedure was first used to directly estimate water content values for eleven pressure heads at each sampling location and then the three water retention models were fitted using the same automated procedure to compute prediction errors. The results show that the non-parametric approach significantly lowered prediction errors for the VG model, while moderately reducing them also for the LN and BC models.
Discussion Paper (PDF, 692 KB) Interactive Discussion (Closed, 11 Comments) Final Revised Paper (HESS)
Citation: Saito, H., Seki, K., and Šimůnek, J.: Geostatistical modeling of spatial variability of water retention curves, Hydrol. Earth Syst. Sci. Discuss., 5, 2491-2522, doi:10.5194/hessd-5-2491-2008, 2008. Bibtex EndNote Reference Manager XML
